• Journal of Biosystems Engineering
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• v.18 no.3
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• pp.209-219
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• 1993

A series of soil bin experiment was carried out on sand to investigate if true model theory is applicable to blade-soil system and finally to find mathematical relationship between the dimensionless terms which contain the blade-soil parameters. The following conclusions were derived from the study. 1. It was proved that the draft of the prototype blade can be predicted without distortion by those of model blades with the length scale of 1.2, 2 and 2.4. 2. For the sand, bulk density was found to be a good measure of soil physical properties which are pertinent to predict the draft of the blade-soil system. 3. The mathematical relationship between $D/{\gamma}W$ and d/W, ${\beta}$, and $V^2/Wg$ are as follows ; $$\frac{D}{{\gamma}W^3}=124.98[\frac{d}{W}]^2+7.16[\frac{d}{W}]+0.43 \\ \frac{D}{{\gamma}W^3}=-0.00099{\beta}^2+0.13{\beta}-2.01 \\ \frac{D}{{\gamma}W^3}=0.041[\frac{V^2}{Wg}]^2+0.08[\frac{V^2}{Wg}]+1.3$$

• Steel and Composite Structures
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• v.43 no.5
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• pp.639-660
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• 2022

The bending and buckling behaviours of FG-GRNC laminated sandwich plates are investigated by using novel five-variables quasi 3D higher order shear deformation plate theory by considering the modified continuum nonlocal strain gradient theory. To calculate the effective Young's modulus of the GRNC sandwich plate along the thickness direction, and Poisson's ratio and mass density, the modified Halpin-Tsai model and the rule of the mixture are employed. Based on a new field of displacement, governing equilibrium equations of the GRNC sandwich plate are solved using a developed approach of Galerkin method. A detailed parametric analysis is carried out to highlight the influences of length scale and material scale parameters, GPLs distribution pattern, the weight fraction of GPLs, geometry and size of GPLs, the geometry of the sandwich plate and the total number of layers on the stresses, deformation and critical buckling loads. Some details are studied exclusively for the first time, such as stresses and the nonlocality effect.

• Journal of the Korean Society of School Health
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• v.26 no.3
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• pp.184-194
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• 2013

Purpose: The purpose of this study was to investigate predictors of behavior problems of military children in elementary school. Methods: Participants were 195 military children who were attending D-elementary school in C-city. Data were collected from July 8 to July 10, 2013, using self-report questionnaires which included Han's Externalized Behavior Problems Scale, Lee's Parent's Rearing Attitude Scale, and Hong's Friend/Teacher Support Appraisal Scale. Data analysis was performed using the SPSS/WIN 18.0 program, which included the t-test, the one-way ANOVA, Pearson correlation coefficients, and the multiple liner regression analysis. Results: The mean score of the subjects' behavior problem was 1.47/5.0 points. The degree of the score is similar to or slightly lower than that of ordinary children. There were statistically significant differences in behavior problems according to gender, grade, birth order and economic status. Behavior problems have a negative correlation with parent's rearing attitude, parent-child relationship, teacher's support, and friend's support. Influencing factors of behavior problems were teacher's support, father-child relationship, and mother's rearing attitude, which explained 20.6% of the variance. Conclusion: The finding of this study suggests there is a need to increase teacher's support for elementary students and to educate parents to improve their parenting skills by developing proper school health programs.

• Korean Journal of Child Studies
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• v.32 no.6
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• pp.33-48
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• 2011

This study examined the relationships between place attachment to home, acculturative stress, and psychological adjustment among Korean youth in the United States. In particular, this study sought to better understand how place attachment to home and acculturation stress impacts upon youth's psychological adjustment, as measured by depression and self-esteem. The subjects consisted of 225 Korean youths (113 males and 111 females) residing in Michigan in the USA, of whom 47.6% attended middle school while 52.4% of whom attended high school. The instruments utilized were the acculturative stress scale (Sandhu and Asrabadi, 1994), the place attachment scale (Choi, Lee, & Han, 2009), Radloff's depression scale (CES-D), and Rosenberg's self-esteem scale. Hierarchical multiple regression analyses were used to assess the predictive effects of place attachment to home and acculturative stress on youth's psychological adjustment, alongside controlling demographic variables. The findings indicated that place attachment to home and acculturative stress impacted upon depression and self-esteem, as experienced by the youths examined. These results have implications for our understanding of the importance of both youths' place attachment to home and acculturative stress in the acculturation process.

• Explosives and Blasting
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• v.8 no.1
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• pp.3-16
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• 1990

The cautious blasting works had been used with emulsion explosion electric M/S delay caps. Drill depth was from 3m to 6m with Crawler Drill $\varphi{70mm}$ on the calcalious sand stone(sort-moderate-semi hard Rock). The total numbers of feet blast were 88. Scale distance were induces 15.52-60.32. It was applied to propagation Law in blasting vibration as follows. Propagtion Law in Blasting Vibration $V=K(\frac{D}{W^b})^n$ where V : Peak partical velocity(cm/sec) D : Distance between explosion and recording sites (m) W : Maximum Charge per delay-period of eighit milliseconds or more(Kg) K : Ground transmission constant, empirically determind on th Rocks, Explosive and drilling pattern ets. b : Charge exponents n : Reduced exponents Where the quantity $D/W^b$ is known as the Scale distance. Above equation is worked by the U.S Bureau of Mines to determine peak particle velocity. The propagation Law can be catagrorized in three graups. Cabic root Scaling charge per delay Square root Scaling of charge per delay Site-specific Scaling of charge per delay Charge and reduction exponents carried out by multiple regressional analysis. It's divided into under loom and over loom distance because the frequency is verified by the distance from blast site. Empirical equation of cautious blasting vibration is as follows. Over 30m----under l00m----- $V=41(D/3\sqrt{W})^{-1.41}$ -----A Over l00m-----$V= 121(D/3\sqrt{W})^{-1.66}$-----B K value on the above equation has to be more specified for furthur understang about the effect of explosives, Rock strength. And Drilling pattern on the vibration levels, it is necessary to carry out more tests.

• Explosives and Blasting
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• v.9 no.4
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• pp.3-12
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• 1991

The cautious blasting works had been used with emulsion explosion electric M /S delay caps. Drill depth was from 3m to 6m with Crawler Drill 70mm on the calcalious sand stone (soft-moderate-semi hard Rock) . The total numbers of feet blast were 88. Scale distance were induces 15.52-60.32. It was applied to Propagation Law in blasting vibration as follows .Propagtion Law in Blasting Vibration V=k(D/W/sup b/)/sup n/ where V : Peak partical velocity(cm/sec) D : Distance between explosion and recording sites(m) W ; Maximum Charge per delay -period of eight milliseconds or more(Kg) K : Ground transmission constant, empirically determind on the Rocks, Explosive and drilling pattern ets. b : Charge exponents n : Reduced exponents Where the quantity D/W/sup b/ is known as the Scale distance. Above equation is worked by the U.S Bureau of Mines to determine peak particle velocity. The propagation Law can be catagrorized in three groups. Cabic root Scaling charge per delay Square root Scaling of charge per delay Site-specific Scaling of charge delay Charge and reduction exponents carried out by multiple regressional analysis. It's divided into under loom and over loom distance because the frequency is varified by the distance from blast site. Empirical equation of cautious blasting vibration is as follows. Over 30m--under 100m----V=41(D/ W)/sup -1.41/-----A Over l00m---------V=121(D/ W)/sup -1.56/-----B K value on the above equation has to be more specified for furthur understand about the effect of explosives. Rock strength, And Drilling pattern on the vibration levels, it is necessary to carry out more tests.

• The Journal of Engineering Geology
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• v.32 no.4
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• pp.449-466
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• 2022

The establishment of a complete geological model that includes information about all the various components at a site (such as underground structures and the compositions of rock and soil underground space) is difficult, and geological modeling is a developing field. This study uses commercial software for the relatively easy composition of geological models. Our digital modeling process integrates a model of Jeju Island's 3D geological information, models of cave shapes, and information on the state of a road at the site's upper surface. Among the numerous natural caves that exist in Jeju Island, we studied the Jaeamcheon lava tube near Hallim town, and the selected site lies below a road. We developed a digital model by applying the principles of building information modeling (BIM) to the cave (CaveBIM). The digital model was compiled through gathering and integrating specific data: relevant processes include modeling the cave's shape using a laser scanner, 3D geological modeling using geological information and geophysical exploration data, and modeling the surrounding area using drones. This study developed a global-scale model of the Hallim region and a local-scale model of the Jaeamcheon cave. Cross-validation was performed when constructing the LSM, and the results were compared and analyzed.

• Journal of the Korean Institute of Gas
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• v.21 no.5
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• pp.45-55
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• 2017

Release and fire/explosion tests of flammable gas are extremely dangerous. Furthermore, it is difficult to select the site where the experiment can be performed. In these reasons, gas flow analysis(CFD) has been used as much as possible. However, with the opening of the Energy Safety Empirical Research Center in Yeongwol-gun, Gangwon-do in October 2016, it was possible to conduct releases and detection tests of small scale combustible gas as well as large scale / high pressure / ultra low temperature experiments. In this study, LPG leaked after the calibration and placement of the sensor, the sensor detected LPG and the data were visualized as a contour map. And the differences between the actual release(28s, max 3.7[m]) and the analysis were analyzed compared to the FLACS analyzed under the same conditions.

• Journal of Oriental Neuropsychiatry
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• v.32 no.3
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• pp.155-166
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• 2021

Objectives: To analyze correlation between CSEI-S and MMPI-2 subscales to provide evidence for clinical application of the CSEI-S. Methods: Survey data of CSEI-S and MMPI-2 from 109 university students were analyzed. Demographic characteristics were subjected to descriptive analysis. Mann-Whitney U test and Pearson's correlation analysis were performed for CSEI-S and MMPI-2 scores. Results: The CSEI-S scale Joy (喜) showed a negative correlation with MMPI-2 clinical scales Hs, D, Hy, Pd, Pa, Pt, Sc, and Si. Six negative emotion scales of the CSEI-S showed positive correlations with MMPI-2 clinical scales except Mf and Ma. The CSEI-S scale Joy (喜) showed negative correlations with MMPI-2 restructured clinical scales RCd, RC1, RC2, and RC7. Six negative emotion scales of the CSEI-S showed positive correlations with restructured MMPI-2 clinical scales. The 60T-and-over group of MMPI-2 clinical scales D, Pd, Pa, Pt, Sc, Si, and Si showed significantly higher negative emotions than other groups. The 60T-and-over group of MMPI-2 scales D, Pt, Sc, and Si showed significantly lower Joy (喜) score than other groups. The 60T-and-over group of MMPI-2 restructured clinical scales RCd, RC2, RC3, RC6, RC7, RC8, and RC9 showed significantly higher negative emotions than other groups. The 60T-and-over group of MMPI-2 scales RCd, RC6, and RC7 showed significantly lower Joy (喜) scores than others. Conclusions: The CSEI-S showed consistent results with the original CSEI and MMPI-2 subscales. Thus, is a useful diagnostic tool in clinical practice.

• Journal of Sericultural and Entomological Science
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• v.49 no.1
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• pp.28-32
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• 2007

This study was carried out to investigate the utilization of hemolymph of silkworm, Bombyx mori, as a substitute for fetal bovine serum(FBS) in the insect cell culture. Hemolymph is collected on a small scale by clipping the abdominal leg; however, this method is not appropriate for large scale collection. The hemolymph was collected from 5 th instar larva by centrifugation after cutting of the abdominal legs was more appropriate procedure for large scale collection. The cell growth in the medium supplemented with hemolymph(Baekokjam) collected in large scale was almost same as that in the medium hemolymph supplemented with hemolymph collected in small scale. However, the mutant($wE^b$) hemolymph collected in large scale was still less effective in the cell growth, as compared to the Baekokjam hemolymph collected in large scale. The optimum centrifugation condition for large-scale bleeding was 500 rpm and 15 min.